The subject of the present invention is a fabric made up of at least two laps interwoven along a common stretch, as well as the method for its production.
Fabrics with double width, which can be made only with shuttle looms, are used to make fabrics with a width twice what can normally be obtained with the reed width
With said technique, two fabrics are obtained set on top of one another and joined together on one side; once it has come out of the loom, the fabric that is obtained hence has a width twice the reed width.
For production of the above fabric, as may be noted in FIG. 1, it is necessary to combine the weave of the fabric of the front with that of the back, both in the direction of the warp 11 and in the direction of the weft 10.
Weft insertion, in the case of a plain weave, will present the following sequence: the first weft insertion will interweave with the threads of warp yarn of the top fabric 12 (odd threads of yarn of the top fabric on top); the second weft insertion will interweave with the threads of warp yarn of the bottom fabric 13 (odd threads of yarn of the bottom fabric on top and lifting en masse of the threads of yarn of the top fabric), as likewise the third weft insertion (even threads of yarn of the bottom fabric on top and lifting en masse of the threads of yarn of the top fabric); and the fourth weft insertion will interweave with the threads of warp yarn of the top fabric (even threads of yarn of the top fabric on top).
By adopting the above logic, it is possible to obtain fabrics even of triple width 12, 13, 14 and 17, represented in FIG. 2 described below.
Tubular fabrics (illustrated in FIG. 3), which can also be made only with shuttle looms, are constituted by two fabrics 12 and 13 set on top of one another bound together only at the ends 17 through the two selvedges; they are in general used for making bags or sacks, or tubular fabric coatings.
Tubular fabrics differ from the double-width fabrics as regards the system of weft insertion, the sequence of which, in the case of a plain weave is as follows: the first weft will interweave with the threads of warp yarn of the top fabric (odd threads of yarn of the top fabric on top); the second weft with the threads of warp yarn of the bottom fabric (even threads of yarn of the bottom fabric on top and lifting en masse of the threads of yarn of the top fabric); the third weft will interweave with the threads of warp yarn of the top fabric (even threads of yarn of the top fabric on top); and the fourth weft will interweave with the threads of yarn of the bottom fabric (odd threads of yarn of the bottom fabric on top and lifting en masse of the threads of yarn of the top fabric).
If in a tubular fabric the threads of warp yarn and the threads of weft yarn alternate, as may be noted in FIG. 4, an alternating tubular fabric is obtained where the threads of warp yarn and threads of weft yarn that constitute the top fabric 12 and 13 exchange with one another on a longitudinal line 15, then coming to form the bottom fabric 13′ and 12′, as illustrated in FIG. 4.
By adopting the same logic, it is also possible to obtain alternating triple fabrics 12, 13, 16; 16′, 12′, 13′; 13″, 16″, 12″, as illustrated in FIG. 5.